Powered Lathe Slotter Build

[Toolmaker51]

Interesting; I don't recall seeing a lathe-driven shaper. One more instance of lathes being the single most universal machine tool. Shaper motion seem passe to modern machinists, but wire and sinker EDM, hasn't been around forever...or prevalent in home shops.

Occasionally, similar devices were offered for horizontal milling machines. Most swivel CW-CCW, parallel to the vertical [Z] ways.
Have seen a drawing [30's era] that had a tilt feature as well. Photo was of it mounted; probably drove a yoke or crankshaft via helical coupling. Incline was a wedge shaped spacer. It was probably somewhere 3 to 8 degrees to clear backside of die plates.